Build Thread: SMJ-40 PE MOD X

[Scareurpasenger]

I hope it cleans up nicely. That has some beautiful grain patterns to it!

[Steve Manning]

I hope it cleans up nicely. That has some beautiful grain patterns to it!

I was adding a picture as you made this entry. It cleaned up pretty well ..... still have sanding to do of course.

[Scareurpasenger]

That is going to look lovely with a finish on it.

[technodanvan]

Beautiful work Steve! I'm glad we got through the first one with minimal issues!

[Steve Manning]

Beautiful work Steve! I'm glad we got through the first one with minimal issues!

Thanks Danny ..... I'm hoping this was the worst of the bunch for chipping issues.

[Steve Manning]

Slow progress over the last week or so. I had to replace a part on the CNC so I couldn't do anything until that was done.

At this point all 6 bulges have been machined.







Now for a bunch of sanding and applying some finish on these things.

[technodanvan]

These look incredible Steve! I'm going to need several pairs to show them all off...

[letiennam]

they are so beautiful, i wish i was in America. I live in Vietnam and I can only buy 15mm thick Baltic plywood. I will bring it to the CNC wood service provider near my house this Saturday. The above wood panels will be used for Top panel, Back panel, Inner front panel . Can anyone share their experience for CLD construction?

[xandresen]

Can anyone share their experience for CLD construction?

I posted a CLD method here several years ago that I worked out for DIY, you can search for it.

My experiments showed the energy absorbing products we can buy which are designed to damp thin metal in cars and airplanes do not work at all between layers of MDF or Baltic Birch. The wood is just too soft compared to metal.
Other forums wish for magic adhesive caulks to glue panels together into CLD. However Dr Earl Geddes points out that it's additives mixed into the squishy material which control the energy absorption, not the raw adhesive we can buy.

If you want to run an experiment I didn't try (highly recommended)
Make test panels about 0.25M square.
Apply a thin layer (1mm?) of the self-adhesive loaded vinyl used for car door damping to one side of your 15mm BB. Buy acrylic loaded mortar (plain mortar won't stick to vinyl plastic) and trowel a 5-6mm layer on top of the loaded vinyl. Do NOT overlap the mortar onto the wood, the two layers need to flex independently!
In my experiments this second layer must be much stiffer than wood for the automotive loaded vinyl to work. I used thin bathroom tile.

Use a knuckle rap to compare this panel to a panel made by gluing two 15mm panels together with regular wood glue.

Good luck.

If you have more CLD questions, best to start a separate thread.

[Steve Manning]

Well the slow work continues. All the bulges have been sanded up to 220 grit and have inserts installed. With as hard as these woods are installing the inserts was not a lot of fun.



Today was spent trying out a new finish that I came across ..... it cures through UV light. It's supposed to protect the wood from humidity changes, which is a concern with these going to Nevada.



It's tough to see the sheen here (satin) the lower inch of the board has no finish on it. This has 2 coats of sealer and 2 top coats. Everything was applied curried with sanding in between coats in ~45 minutes.

It's a straight forward process though getting the results the developer shows in videos is not so easy. I found that during the curing process, a 2 minute exposure to UV light, heat is generated and creates small bubbles. If you have a nice flat surface like my test piece imperfections can be sanded out. The surface here is glass smooth because I could easily use a sander. That's not going to be the case with the actual parts which will require a fair bit of hand sanding.

Time will tell!

[JonMarsh]

Slow work takes time... Quality work even longer!

[Steve Manning]

Had to take a step or two backwards with the finishing process. I was not having consistent results with the small hand held UV light initially purchased for the process. Ended up having to get something that could be mounted above the parts, rather than trying to hold something stable by hand for several minutes.



At the prescribed height from the part this light provides a roughly 3' X 3' curing area.



Two out of the six parts done.

[technodanvan]

Looking great Steve!

I think I posted earlier about some sales at PE on the drivers in this build. Well, you can get another 15% off the sale price this weekend. I already took advantage on a few things, including the TB coax Jon has been gushing about. FYI - only 20 remain.

[Steve Manning]

Well finally I can say all six of the bulges are done.

This is is the last of the three different species, my personal favorite .....



All six together .....

[JonMarsh]

I like your favorite, too, but then I have a lot of samples of cool older wood that's hard to get now.

[technodanvan]

This is going to be a hard decision Steve, they all look fantastic! Maybe change with the season?

[JonMarsh]

There you go, Danny... but how do you choose which one for which season?

[technodanvan]

Man, I don't even know what color to paint the rest of the cabs now. White or black? Matte, satin, or gloss? I'll have a set of five of these bulges to play with so whatever I choose it'll need to go with all of them.

[Steve Manning]

Man, I don't even know what color to paint the rest of the cabs now. White or black? Matte, satin, or gloss? I'll have a set of five of these bulges to play with so whatever I choose it'll need to go with all of them.

Well as the saying goes you have choices! These are supposed to be a satin finish, though they seem more on the glossy side to me. You could hit them with a high grit, ~5000 or so, sandpaper and dull the finish a bit?

[technodanvan]

Now that the holidays are over, Steve mailed out the parts for this build. His packaging is nearly as impressive as the products themselves!



Of course, I still don't know when I'll get to these. I'm just hoping no significant warpage will occur. I think the steps we took should alleviate that for the most part, but still, I worry.